"This follows your article in The Sunday Telegraph about what you call a Green Brexit and proposing a statutory environmental champion. You do not, of course, need Brexit to deliver such a champion and Parliament could not bind its successors regarding its remit.It was a step forward in the 1990s when the Conservative Government established the Environment Agency. After an uncertain start it then matured, with Barbara Young as Chief Executive, as an environmental regulator and there are perhaps two immediately pertinent issues:

1 it combined the roles of environmental regulator, environmental advocate and undertaker of major public works. While the founding Secretary of State in creating a strong unified body for the environment might have made a step forward at the time, there is a case - with a Member State committed to the acquis - for disaggregating these functions; but

2 the Agency has not since 2010 proved effective at holding HMG at arm’s length: its operations have been more integrated with DEFRA’s. This is not exactly reliable evidence of enduring intent as regards your proposed champion.

The terms in which you refer to EU policies do not mitigate doubt. Indeed, it is hard to resist the suspicion that you propose a champion now to try to disarm the EU in the context of Brexit by appearing to neutralise comments of those of your closest colleagues who make no secret of their ambition to de-regulate and to undermine the precautionary principle.

Nor does talking down the EU’s environmental acquis constitute evidence of your Government’s wish and ability to do better. The practical reality has too often been of the UK government privately resisting environmental advance: might it perhaps be wiser not to provoke a reaction by disparaging the European Commission’s performance? That said, we would lobby for enhancing the power of the European Environment Agency so that it annually publishes audits of Member States’ environmental regulators in delivering compliance with the environmental acquis.

It is a fairly typical chronology that in 2013 your party resisted the EU’s proposed ban on neonicotinoids but now, following your recent announcement (which does not extend to opposing glyphosate), Conservative Party propaganda hails HMG as the bees’ saviour. The UK has too often struggled to attain EU environmental standards long regarded as a basic minimum by our most comparable EU neighbours.

To demonstrate that a Brexit Britain would be anything other than a return to a Dirtier Britain requires satisfying a very much higher evidential burden than proposing an advocate."